This invention relates to crushers, such as shredders, hammermills and ringmills used to process ferrous and non-ferrous scrap material, and, in particular, to an improved rotor shaft for use with the crusher/shredder.
Crushers, shredders, hammermills, ringmills, and the like, are often used to process scrap material and stone, to crush or reduce the size of the material so that it can more easily be handled by other equipment for further processing or use.
Such crushers typically include a plurality of hammers or rings mounted about a rotatable shaft. As the shaft rotates, the hammers or rings engage and crush whatever media is introduced into the crusher. The hammers or rings can be mounted between supports in the form of spiders or center discs which are positionally fixed relative to the rotor shaft. Typically, the rotor shaft is cylindrical. The use of a cylindrical shaft requires that the supports be positively keyed to the shaft, for example, using a square or rectangular key on the support and a corresponding keyway on the shaft, so that the support cannot rotate relative to the shaft. The use of a keyway weakens the main shaft and makes removal of the supports and end discs a much more difficult task. Further, the key will weaken over time, and eventually the rotor assembly will shift between the shredder housings. Obviously, this can necessitate a repair of the crusher/shredder, requiring that operation of the crusher/shredder be stopped for the duration of the repair. Depending on the location of the support which is no longer positively fixed with respect to the shaft, the crusher/shredder can be shut down for a considerable period of time.